Yemeni medics and activists say fighting between government forces and opposition fighters in the country's third-largest city has killed at least nine people.

They say troops loyal to President Ali Abdullah Saleh fired tank and mortar shells at several neighborhoods in the southern city of Taiz on Wednesday. Taiz has been a hub of a nine-month uprising against Mr. Saleh's 33-year rule.

Witnesses say dissident army units fired back at the pro-Saleh forces. They say several civilians were among those killed, while another 40 people were wounded.

The French news agency says Yemeni government troops also battled fighters loyal to an opposition tribal chief in the capital, Sana'a late Tuesday. It says three people were killed in the fighting.

President Saleh has refused to sign a U.N.-backed plan to hand power to a deputy within 30 days in return for immunity from prosecution. Instead, he has demanded international guarantees about a timetable for implementing the Gulf Cooperation Council proposal.

On Tuesday, Yemen's state-run SABA news agency quoted a European Union envoy as saying Mr. Saleh has moved closer to accepting the GCC plan.